\documentclass{article}
\usepackage[x11names, rgb]{xcolor}
\usepackage[utf8]{inputenc}
\usepackage{tikz}
\usetikzlibrary{snakes,arrows,shapes}
\usepackage{amsmath}
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\usepackage[active,tightpage]{preview}
\PreviewEnvironment{tikzpicture}
\setlength\PreviewBorder{0pt}%
\usetikzlibrary{automata}%

\begin{document}
\pagestyle{empty}
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\enlargethispage{100cm}
% Start of code
\begin{tikzpicture}[>=latex',join=bevel,]
\tikzstyle{every state}=[draw=blue!50,very thick,fill=blue!20]%
\node (q0) at (363bp,634bp) [state] {$q_{0}$};
  \node (q2) at (232bp,458bp) [state] {$q_{2}$};
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  \draw [->] (q2) ..controls (177bp,447bp) and (132bp,435bp)  .. (123bp,422bp) .. controls (118bp,415bp) and (117bp,406bp)  .. node[auto] {$\overline{auctionRegistrationService#process}$} (q3);
  \draw [->] (q3) ..controls (123bp,340bp) and (123bp,324bp)  .. node[auto] {$auctionRegistrationService#answer$} (q4);
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\end{tikzpicture}
% End of code

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\end{document}
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